ar y n i im prel iC-NZN N-TYPE LASER DIODE DRIVER Rev B1, Page 1/17 FEATURES APPLICATIONS ♦ Peak value controlled laser diode driver for operation from CW up to 155 MHz ♦ Spike-free switching of laser currents of up to 300 mA ♦ Setting of laser power (APC) via external resistor ♦ Optional current control (ACC) ♦ Laser current limitation ♦ LVDS/TTL switching input with TTL monitor output ♦ Low current consumption sleep-mode < 50 µA ♦ Safety shutdown with overtemperature ♦ Error signal output with overtemperature, undervoltage and overcurrent ♦ All current LD types can be used (N/P/M configurations) ♦ Blue laser diodes supported ♦ Fast soft-start ♦ Strong suppression of transients with small external capacitors ♦ Pulsed and CW laser diode modules ♦ Laser diode pointers ♦ Laser levels ♦ Bar-code readers ♦ Distance measurement ♦ Blue laser diodes PACKAGES QFN24 4 mm x 4 mm BLOCK DIAGRAM RVDD +3..+5.5V VDD CVDD RSI RSI NSLP REGE CLDA iC-NZN LDA MONITOR 100 nF.. 0.68.. 9kΩ LDA i(RSI)x540 IMON VDD & AVG ..300mA 1 & VSY REF SYN EP 100 nF.. N LDK + CI - LVDS/TTL ECI + EN CI x240 - CIS ..10 nF.. AGND VDD TTL MD CID ECI OUTPUT DRIVER INPUT INTERFACE NERR RMD OverTemp. 1 GND OverCurrent Bandgap, Reference, Overtemp Low V(LDA) T.PAD OUTPUT MONITOR GND PMD RGND suitable laser diode configurations N Copyright © 2011 iC-Haus M P http://www.ichaus.com ar y n i im prel iC-NZN N-TYPE LASER DIODE DRIVER Rev B1, Page 2/17 DESCRIPTION Laser diode pulse driver iC-NZN allows CW operation of laser diodes and spike-free switching with defined current pulses up to 155 MHz. The optical output power of the laser diode is set-up by means of an external resistor (RMD/PMD). For laser current control without a monitor diode, the laser current monitor at pin IMON is utilised. For high pulse frequencies the device can be switched into controlled burst mode. A previously settled operating point is maintained throughout the burst phase. An averaging current monitor can be set by means of an external resistor at pin RSI. When the current limit is reached, overcurrent is signalled at NERR and the current from pin LDA is limited to the pre-set value but the iC is not shut down. There is an additional current limitation in pin LDK that prevents the iC from overpowering the laser diode. Setting pin NSLP low, the iC enters a low consumption sleep-mode (< 50 µA typ.). PACKAGES QFN24 4 mm x 4 mm to JEDEC PIN CONFIGURATION 24 23 PIN FUNCTIONS No. Name Function 22 21 20 19 1 18 2 17 16 3 NZN code... ... 4 5 15 14 13 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 VDD AVG MD IMON CID EP EN TTL VSY SYN RGND RVDD LDK AGND CIS CI LDA Power Supply Enable Averaging Control APC setup, monitor input Laser Current Monitor Enable Pulldown Current at CI Positive LVDS/TTL switching input Negative LVDS switching input Enable TTL input Sync Output Supply Voltage Sync Output Reference Ground Reference (P-type laser diodes) Laser Diode Cathode Analog ground Power Control Capacitor sense Power Control Capacitor Laser Diode Anode n/c RSI Current Monitor Setup REGE Control Enable GND Ground NSLP Not Sleep-Mode NERR Error Output n/c The Thermal Pad is to be connected to a Ground Plane (GND) on the PCB. Only pin 1 marking on top or bottom defines the package orientation ( NZN label and coding is subject to change). ar y n i im prel iC-NZN N-TYPE LASER DIODE DRIVER Rev B1, Page 3/17 PACKAGE DIMENSIONS RECOMMENDED PCB-FOOTPRINT 3.80 2.49 15 R0. TOP 0.30 0.70 0.50 0.25 0.40 3.80 0.90 2.49 SIDE BOTTOM 2.45 4 2.45 4 0.50 dra_qfn24-1_pack_1, 10:1 All dimensions given in mm. iC-NZN N-TYPE LASER DIODE DRIVER ar y n i im prel Rev B1, Page 4/17 ABSOLUTE MAXIMUM RATINGS Beyond these values damage may occur; device operation is not guaranteed. Item No. Symbol Parameter Conditions Unit Min. Max. G001 VDD Voltage at VDD -0.7 6 V G002 I(VDD) Current in VDD DC current -2 1200 mA G003 I(CI) Current in CI V(LDA) = 0 -2 5 mA G004 I(NERR) Current in NERR -2 20 mA G005 I(MD) Current in MD -2 20 mA G006 I()dig Current in EP, EN, TTL, REGE, NSLP, AVG, CID -2 20 mA G007 I(LDK) Current in LDK DC current -2 1200 mA G008 I(LDA) Current in LDA DC current -2 1200 mA G009 I(RSI) Current in RSI -2 20 mA G010 I(VSY) Current in VSYNC -2 50 mA G011 I(SYN) Current in SYNC -2 50 mA G012 I(IMON) Current in IMON -2 20 mA G013 V()c Voltage at RSI, VSY, SYN, EP, EN, TTL, REGE, AVG, CID, RGND, MD, CI, IMON, RVDD, LDA, NERR, NSLP -0.7 6 V G014 V()h Voltage at LDK -0.7 15 V G015 Vd() ESD Susceptibility at all pins 2 kV G016 Tj Operating Junction Temperature -40 190 °C G017 Ts Storage Temperature Range -40 190 °C HBM, 100 pF discharged through 1.5 kΩ THERMAL DATA Operating Conditions: VDD = 3...5.5 V Item No. Symbol Parameter Conditions Unit Min. T01 Ta Operating Ambient Temperature Range T02 Rthja Thermal Resistance Chip/Ambient Typ. -20 surface mounted, thermal pad soldered to ca. 2 cm² heat sink All voltages are referenced to ground unless otherwise stated. All currents flowing into the device pins are positive; all currents flowing out of the device pins are negative. 30 Max. 85 °C 40 K/W iC-NZN N-TYPE LASER DIODE DRIVER ar y n i im prel Rev B1, Page 5/17 ELECTRICAL CHARACTERISTICS Operating Conditions: VDD = 3...5.5 V, VSY = 0 V...VDD, Tj = -20...125 °C, NSLP = hi, CID = lo; unless otherwise stated Item No. Symbol Parameter Conditions Unit Min. Typ. Max. Total Device 001 VDD Permissible Supply Voltage 002 VSY Permissible Supply Voltage at VSY VSY ≤ VDD 003 Ioff(VDD) Supply Current in VDD NSLP = lo, all other input pins set to lo 5 50 µA 004 Idc(VDD) Supply Current in VDD RSI ≥ 680 Ω 10 15 mA 005 I(VSY) Supply Current in VSY SYN pin open 10 µA 006 Tab Thermal Shutdown Threshold 130 196 °C 007 VDDon Power-On Threshold 1.7 2.8 V 008 Vc()hi Clamp Voltage hi at RSI, TTL, REGE, MD, CI, LDA, NSLP, IMON 0.3 1.5 V 009 Vc()hi Clamp Voltage hi to VSY at SYN I() = 1 mA, other pins open, VSY = 0 0.3 1.5 V 010 Vc()hi Clamp Voltage hi at LDK I() = 1 mA, other pins open 12 011 Vc()lo Clamp Voltage lo at VDD, AVG, MD, IMON, CID, EP, EN, TTL, VSY, SYN, RGND, RVDD, LDK, AGND, CI, LDA, RSI, REGE, NSLP, NERR I() = 1 mA, other pins open -1.5 012 Vc()hi Clamp Voltage hi at VSY, EP, EN I() = 1 mA, other pins open, VDD = 0 I() = 0.1 mA, other pins open, VDD = 0 3 5.5 V 3 5.5 V V -0.65 -0.3 V 6 V 580 mV 9 9 kΩ kΩ 630 mV 880 630 mA mA Current Monitor RSI, LDA 101 102 V(RSI) Voltage at RSI RSI Permissable Resistor at RSI VDD = 3...3.5 V VDD = 4.5...5.5 V 2.5 0.68 103 104 VLDA LDA Voltage Monitor Threshold VDD − V(LDA), V(RSI) = VDD 400 Ierr(LDA) Maximum Unlimited current from V(RSI) = VDD; VDD = 4.5...5.5 V LDA without error signaling VDD = 3...3.5 V 105 Cmin(LDA) Minimum capacitor needed at LDA 106 rILDA 107 rILDK Current Ratio I(LDA)max / I(RSI) Current Ratio I(LDK)max / I(RSI) 108 i(ldk) 109 Rdis(LDA) Discharge Resistor at LDA Maximum limited current 430 520 500 400 260 100 nF V(LDA) = 0 V VDD = 4.5...5.5 V VDD = 3...3.5 V 470 430 610 610 V(LDK) = V(REGE) = V(TTL) = V(EP) = VDD, V(MD) = 0 V VDD = 4.5...5.5 V VDD = 3...3.5 V 400 480 960 870 RSI = 0.68 KΩ VDD = 5.5 V NSLP = lo, V(LDA) = VDD 1 630 mA 20 kΩ 560 mV Reference 201 V(MD) V(MD) − V(RGND), closed control loop V(RVDD) − V(MD) for P-type LD or ACC 202 dV(MD) Temperature Drift of Voltage at MD closed control loop 203 V(MD) V(MD) − V(RGND) V(EP) = 0 V, V(AVG) = 0 V, N-type LD 460 460 510 120 510 µV/°C 560 mV VDD 1.4 V Digital Inputs/Outputs 301 Vin() Input Voltage Range at EP, EN TTL = lo, VDD = 3.0...5.5 V 0.6 302 Vd() Input Differential Voltage at EP, EN TTL = lo, Vd() = |V(EP) - V(EN)| 200 303 R() Differential Input Impedance at EP, EN TTL = lo V(EP), V(EN) < VDD − 1.5 V 0.6 304 Vt(EP)hi Input Threshold Voltage hi at EP TTL = hi, EN = open 305 Vt(EP)lo Input Threshold Voltage lo at EP TTL = hi, EN = open 0.8 mV 3 kΩ 2 V V iC-NZN N-TYPE LASER DIODE DRIVER ar y n i im prel Rev B1, Page 6/17 ELECTRICAL CHARACTERISTICS Operating Conditions: VDD = 3...5.5 V, VSY = 0 V...VDD, Tj = -20...125 °C, NSLP = hi, CID = lo; unless otherwise stated Item No. Symbol Parameter Conditions Unit Min. 306 Vhys(EP) Hysteresis at EP TTL = hi, EN = open 40 307 Ipd(EP) Pull-Down Current at EP TTL = hi, EN = open, V() = 1 V...VDD 0.5 308 Vt()hi Input Threshold Voltage hi at TTL, REGE, NSLP, AVG, CID 309 Vt()lo Input Threshold Voltage lo at TTL, REGE, NSLP, AVG, CID 0.8 310 Vhys() Hysteresis at TTL, REGE, NSLP, AVG, CID 140 311 Ipu() Pull-Up Current at TTL, REGE 312 Ipd() Pull-Down Current at NSLP, AVG, V() = 1 V...VDD CID 313 Vs()hi Saturation voltage hi at SYN 314 Vs()lo 315 V() = 0...VDD − 1.2 V Typ. Max. mV 5 µA 2 V V 230 mV -60 -2 µA 2 130 µA Vs(SYN)hi = VSY − V(SYN), I() = -1 mA, VSY = VDD, EP = TTL = High, EN = open 0.4 V Saturation voltage lo at SYN I() = 1 mA, TTL = High, VSY = VDD, EP = Low, EN = open 0.4 V Isc()hi Short-circuit Current hi at SYN EP = TTL = High, EN = open, V(SYN) = 0 V, VSY = VDD -40 -3 mA 316 Isc()lo Short-circuit Current lo at SYN EP = TTL = High, EN = open, V(SYN) = 0 V, VSY = VDD 3 25 mA 317 I(NERR) Current in NERR V(NERR) > 0.6 V, error 1 318 Vs()lo Saturation Voltage lo at NERR I() = 1 mA, error Laser Driver LDK, CI, IMON 401 Vs(LDK)lo Saturation Voltage lo at LDK I(LDK) = 300 mA, RSI = 680 Ω, VDD=4.5...5.5 V I(LDK) = 100 mA, RSI = 680 Ω VDD=4.5...5.5 V I(LDK) = 60 mA, RSI = 2.5 kΩ VDD=3...3.5 V 1.6 1.2 0.8 20 mA 600 mV 3 2 1.3 V V V mA 402 Idc(LDK) Permissible DC Current in LDK 300 403 Vo() Permissible Voltage at LDK 12 404 405 C(CI) Required Capacitor at CI |I(CI)| Charge Current from CI 0 iC active, REGE = hi, V(CI) = 1 V, CID = 0 V iC active, REGE = hi, V(CI) = 1 V, CID = VDD 10 V nF 20 0 65 µA µA 406 Ipd(CI) Pull-Down Current in CI iC active, REGE = lo, CID = hi, V(CI) = 1 V, VDD = 3...5.5 V 0.3 2.6 µA 407 Imon() Current at IMON V(IMON) = VDD − 0.5 V, I(LDK) < 300 mA, VDD = 4.5...5.5 V 1/280 1/200 I(LDK) 408 Imin(LDK) Minimum permissible current pulse 0.5 mA 409 Imax(LDK) Maximum obtainable current from V(REGE) = V(TTL) = V(EP) = VDD, the driver V(MD) = 0 V; VDD = 4.5...5.5 V VDD = 3...4.5 V 300 90 mA mA Timing 501 twu Time to Wakeup: NSLP lo → hi to system enable CLDA = 1 µF, RSI = 680 Ω 300 µs 502 tr Laser Current Rise Time VDD = 5 V see Fig. 2 1.5 ns 503 tf Laser Current Fall Time VDD = 5 V see Fig. 2 1.5 ns 504 tp Propagation Delay V(EPx, ENx) → I(LDKx) VDD = 5 V 10 ns ar y n i im prel iC-NZN N-TYPE LASER DIODE DRIVER Rev B1, Page 7/17 ELECTRICAL CHARACTERISTICS: DIAGRAMS I(LED) tr tf I pk V 90% I pk Input/Output VDD−0.45V Vt()hi Vt()lo 0.45V 1 t 10% I pk t 0 Figure 1: Reference levels Figure 2: Laser current pulse ar y n i im prel iC-NZN N-TYPE LASER DIODE DRIVER Rev B1, Page 8/17 DESCRIPTION OF FUNCTIONS iC-NZN is a laser diode pulse driver. The device features the following functions: • Extension of the laser current with few external components • • • • • Operation of blue laser diodes possible Peak or averaging control Optical power (APC) or current control (ACC) Pulses of up to 155 MHz in controlled burst mode Laser current limitation • Error signalling for overcurrent • Sleep mode with less than 50 µA consumption OPTICAL POWER CONTROL The iC-NZN supports the control of the laser diode’s optical output power for all common laser diode pin configurations (N, P and M). The control is enabled with pin REGE set to high. With AVG set to low, the peak power control is enabled. The laser power level is selected by means of the resistor RMON (= RMD + PMD). This control mode can be used for frequencies up to ca. 4 Mhz. For higher frequencies the averaging control (AVG = high) or the burst mode have to be used. Tables 4 and 5 show how to set the inputs for laser control depending on the input interface selected (TTL or LVDS). Laser control in TTL mode (TTL = high/open) EP EN NSLP REGE SYN Mode low/open Power-save mode low/open open high low LDA charged, laser off high open high high/open high LDA charged, laser on, peak control high open high low high LDA charged, laser on, burst mode Table 4: Laser control in TTL mode Laser control in LVDS mode (TTL = low) EP EN NSLP REGE SYN low/open < EN > EP high low > EN < EP high high/open high > EN < EP high low high Mode Power-save mode LDA charged, laser off LDA charged, laser on, peak control LDA charged, laser on, burst mode Table 5: Laser control in LVDS mode RMON dimensioning Peak control (AVG = low): In order to calculate the right value of RMON, the value of IM (monitor current with respect to optical output power) of the laser diode must be known. RMON must be chosen in a way that the monitor current generated by the desired output power creates a voltage drop across RMON of 500 mV (cf. Electrical Characteristics No. 201). Averaging control (AVG = high): In this mode the calculation is the same as in peak control, only the result has to be divided by the duty cycle of the laser pulses, D = Tτ . At a duty cycle of e.g. 50% D = 21 . This requires an external averaging capacitor of sufficient size at pin CI though. Control modes Averaging Operation mode RMON calculation AVG = 0 Peak control RMON = AVG = 1 Averaging control RMON = V (MD) IM V (MD) IM×D Table 6: RMON dimensioning Example By way of example, an output level of 1 mW is to be set. With an optical power of 1 mW e.g. laser diode HL6339G has a typical monitor current (IM) of 15 µA. The following value is then obtained for the resistor at pin MD (RMON = PMD + RMD, where RMD is a fixed resistor and PMD a potentiometer.): ar y n i im prel iC-NZN N-TYPE LASER DIODE DRIVER Rev B1, Page 9/17 External capacitor mode In applications where an external capacitor is required (see best performance recommendations below), the external capacitor mode must be enabled (pin CID = high). This connects the capacitor to the control circuit and additionally enables a pull-down current at pin CI to prevent this capacitor from being charged due to residual currents (cf. Electrical Characteristics No. 406). lead to an unstable control circuit under certain conditions such as inadequate PCB layout or laser diodes with very low monitor current. In these cases, an optional capacitor can be connected as close as possible to the chip, across pin CI and CIS. This will prevent instability of the control circuit. For averaging control a 10 nF capacitor at CI is recommended. Special care must be taken in PCB layout when laying out the path from the laser diode’s cathode via pin LDK to AGND. This path must be kept as short as possible to avoid parasitic inductances. A sbubber network across the laser diode helps to compensate for these parasitic inductances. Best performance recommendations The operating point for the laser diode is stored in an on-chip capacitor. This permits a fast start-up but can Figures 3, 4 and 5 show the typical set-up for the different N, P and M-type diode configurations. V (MD) 0.5 V RMON = = = 33.34 kΩ IM 15 µA N-type diodes RVDD +3..+5.5V VDD CVDD RSI RSI NSLP REGE CLDA iC-NZN LDA MONITOR 100 nF.. 0.68.. 9kΩ LDA i(RSI)x540 IMON VDD & AVG ..300mA 1 & VSY REF SYN EP 100 nF.. N LDK + CI - LVDS/TTL ECI + EN CI x240 - CIS ..10 nF.. AGND VDD TTL MD CID ECI OUTPUT DRIVER INPUT INTERFACE NERR RMD OverTemp. 1 GND T.PAD OverCurrent Bandgap, Reference, Overtemp Low V(LDA) GND OUTPUT MONITOR PMD RGND Figure 3: Circuit example for N-type laser diodes P-type diodes Althought this kind of laser diodes are supported by iCNZN, it’s strongly recommended to use iC-NZP instead since in this configuration, all the pulses at LDK will be coupled directly to pin MD due to monitor diode’s internal capacitance, thus making an accurate control much more difficult. Moreover, applications with P-type laser diode case grounded are possible with iC-NZP only. ar y n i im prel iC-NZN N-TYPE LASER DIODE DRIVER Rev B1, Page 10/17 RVDD +3..+5.5V VDD CVDD RSI NSLP 0.68.. 9kΩ REGE 100 nF.. LDK AVG ..300mA 1 & VSY REF SYN + CI x240 CI - LVDS/TTL ECI + - EN TTL P IMON VDD & EP CLDA iC-NZN LDA MONITOR 100 nF.. RMD LDA i(RSI)x540 RSI PMD CIS ..10 nF.. AGND VDD MD CID ECI OUTPUT DRIVER INPUT INTERFACE NERR OverTemp. OverCurrent Low V(LDA) 1 T.PAD GND Bandgap, Reference, Overtemp OUTPUT MONITOR GND RGND Figure 4: Circuit example for P-type laser diodes. M-type diodes RVDD +3..+5.5V VDD CVDD 0.68.. 9kΩ CLDA iC-NZN LDA MONITOR 100 nF.. RSI LDA i(RSI)x540 RSI NSLP 100 nF.. LDK REGE & AVG ..300mA 1 & VSY REF SYN EP M IMON VDD + CI - LVDS/TTL ECI + EN CI x240 - CIS ..10 nF.. AGND VDD TTL MD CID ECI OUTPUT DRIVER INPUT INTERFACE NERR RMD OverTemp. 1 GND T.PAD OverCurrent Bandgap, Reference, Overtemp Low V(LDA) GND OUTPUT MONITOR PMD RGND Figure 5: Circuit example for M-type laser diodes Althought this type of laser diode are supported by iCNZN, it’s strongly recommended to use iC-NZP instead since in this configuration, all the pulses at LDK will be coupled directly to pin MD due to monitor diode’s in- ternal capacitance, thus making an accurate control much more difficult. Moreover, applications with Mtype laser diode case grounded are possible with iCNZP only. iC-NZN N-TYPE LASER DIODE DRIVER ar y n i im prel Rev B1, Page 11/17 LASER CURRENT LIMITATION RSI @ VDD LDA VDD CLDA CVDD i(RSI)x540 100 nF.. RSI RSI 100 nF.. 0.5V 0.68..9 kΩ When dimensioning resistor RSI the following applies (cf. Electrical Characteristics No. 106): + - VDD-0.5V LDA current limitation iC-NZN monitors the average laser current flowing from pin LDA (Figure 6). The DC current limit is set by means of a resistor at pin RSI. Imax (LDA) = 540 × 0.5 V RSI The current limitation can be disabled by connecting pin RSI to VDD. NSLP NERR Overcurrent 1 OverTemp. Figure 6: iC-NZN LDA current limitation iC-NZN features two different current limitations, limiting the average current flowing from pin LDA plus the current flowing into pin LDK. Short pulses at LDA with higher currents are possible as only the DC current is monitored and capacitor CLDA supplies the current for short pulses. LDK current limitation The control circuit also monitors the laser current in pin LDK and limits this current when reaching the threshold also defined by RSI. The following applies (cf. Electrical Characteristics No. 107): Imax (LDK ) = 520 × 0.5 V RSI BURST MODE In controlled burst mode iC-NZN can pulse with up to 155 MHz. Controlled here means that a pre-set operating point is maintained during the burst phase. Therefore an operating point is settled first, for which pin REGE has to be high and the laser diode must be switched on. Once the operating point has been reached the laser diode can be switched off again. The operating point is stored in an on-chip capacitor and when pin REGE is set to low, the burst mode is activated. The pre-set operating point is maintained. For a longer burst mode, an external capacitor can be connected to pin CI. To prevent the laser current from rising due to residual currents, the capacitor is discharged then with a maximum of 150 nA (cf. Electrical Characteristics No. 406). As the capacitor is discharged gradually, the output level must be re-settled again after a certain period, depending on the admissible degradation of the laser output power. ar y n i im prel iC-NZN N-TYPE LASER DIODE DRIVER Rev B1, Page 12/17 CURRENT CONTROL The iC-NZN also supports laser current control, when no monitor diode is present. For that purpose, a fraction of the current flowing trough the laser diode is provided at IMON pin (ILDK / 240, cf. Electrical Charac- teristics No. 407). Tables 7 and 8 show how to set the inputs for laser control depending on the input interface selected (TTL or LVDS). Laser control in TTL mode (TTL = high/open) EP EN NSLP AVG REGE SYN low/open low/open open high low high open high high high/open high Mode Power save mode LDA charged, laser off LDA charged, laser on, regulated Table 7: Laser control in TTL mode Laser control in LVDS mode (TTL = Low) EP EN NSLP AVG REGE SYN low/open < EN > EP high low > EN < EP high high high/open high Mode Power save mode LDA charged, laser off LDA charged, laser on, regulated Table 8: Laser control in LVDS mode The laser current is set by means of resistor RMON (= RMD + PMD). RMON = V (RVDD) − V (MD) IMON Figure 7 shows the typical set-up for current control. External capacitor mode In applications where an external capacitor is required (see best performance recommendations below), the external capacitor mode must be enabled (pin CID = high). This connects the capacitor to the control circuit and additionally enables a pull-down current at pin CI to prevent this capacitor from being charged due to residual currents (cf. Electrical Characteristics No. 406). Best performance recommendations The operating point for the laser diode is stored in an on-chip capacitor. This permits a fast start-up but can make the regulated system unstable under certain conditions such as inadequate PCB layout. In these cases, an optional capacitor can be connected as close as possible to the chip, across pins CI and CIS. Special care must be taken in PCB layout when laying out the path from the laser diode’s cathode via pin LDK to AGND. This path must be kept as short as possible to avoid parasitic inductances. A snubber network across the laser diode also helps to compensate for these parasitic inductances. ar y n i im prel iC-NZN N-TYPE LASER DIODE DRIVER Rev B1, Page 13/17 PMD RMD RVDD +3..+5.5V VDD CVDD LDA i(RSI)x540 RSI RSI NSLP 0.68.. 9kΩ REGE CLDA iC-NZN LDA MONITOR 100 nF.. 100 nF.. IMON VDD LDK & AVG ..300mA 1 & + VSY REF SYN CI - LVDS/TTL EP ..10 nF.. CIS ECI + EN CI x240 - AGND VDD TTL MD CID ECI OUTPUT DRIVER INPUT INTERFACE NERR OverTemp. OverCurrent 1 Bandgap, Reference, Overtemp Low V(LDA) T.PAD GND OUTPUT MONITOR GND Figure 7: Example set-up for current control BLUE LASER DIODES required for the blue laser diodes. Nevertheless, the current limitation protection in pin LKD (cf. Electrical Characteristics No. 107) is still active. Figure 8 shows a typical set-up for blue laser diodes with APC and figure 9 with ACC. With the iC-NZN also blue laser diodes can be driven. Due to the high forward voltage of these laser diodes, an appropriate supply voltage must be provided. The current limitation at pin LDA cannot be used then, since only pin LDK is capable of handling the higher voltage ..12V CL 100 nF.. RVDD +3..+5.5V VDD CVDD RSI RSI 0.68.. 9kΩ iC-NZN LDA MONITOR 100 nF.. NSLP IMON VDD LDK REGE & AVG ..300mA 1 & VSY REF SYN EP M LDA i(RSI)x540 + LVDS/TTL CI ECI + EN CI x240 - CIS ..10 nF.. AGND VDD TTL MD CID ECI INPUT INTERFACE OUTPUT DRIVER NERR RMD OverTemp. 1 GND T.PAD GND OverCurrent Low V(LDA) Bandgap, Reference, Overtemp OUTPUT MONITOR PMD RGND Figure 8: Set-up for blue laser diodes with APC ar y n i im prel iC-NZN N-TYPE LASER DIODE DRIVER Rev B1, Page 14/17 ..12V CL RVDD +3..+5.5V VDD CVDD i(RSI)x540 RSI RSI 0.68.. 9kΩ iC-NZN LDA MONITOR 100 nF.. NSLP 100 nF.. IMON VDD LDK REGE & AVG ..300mA 1 & VSY REF SYN EP PMD RMD LDA + CI - LVDS/TTL ECI + EN CI x240 - CIS ..10 nF.. AGND VDD TTL MD CID ECI OUTPUT DRIVER INPUT INTERFACE NERR OverTemp. 1 GND T.PAD OverCurrent Bandgap, Reference, Overtemp Low V(LDA) GND OUTPUT MONITOR RGND Figure 9: Set-up for blue laser diodes with ACC SLEEP MODE The iC-NZN has a very low consumption sleep mode, e.g. for battery powered applications. With pin NSLP set to low the chip enters the sleep mode and discon- nects pin LDA from the supply. The wake-up time from this sleep mode is about 300 µs. J1-LVDS_N 11 JP11 JP12 J1-LVDS_P 9 J1-TTL 3 J1-GND6 12 J1-GND5 10 J1-GND4 8 J1-GND3 5 J1-GND2 4 J1-GND1 2 J1-GND 1 J1-V5D 6 1 2 JP9 BURST R4 opt JP8 AVG 19 RSI 1 VDD U1 iC-NZN GND 21 GND 23 NERR 5 CID 8 TTL 7 EN 6 EP VDD + - & 1 Low V(LDA) OverTemp. OverCurrent INPUT INTERFACE LVDS/TTL VDD i(RSI)x540 LDA MONITOR 1 OUTPUT DRIVER x240 OUTPUT MONITOR Bandgap, Reference, Overtemp SUB EPAD REF & iC-NZN RGND 11 MD 3 AGND 14 CIS 15 CI 16 LDK 13 IMON 4 LDA 17 RVDD 12 C5 10nF 1 2 C 1 N-Type M-Type (default) 3 3 P-Type ACC 2 L R 10K P1 R1 5.1K 2 3 LDC MDA LDA (default) ACC APC D1 JP1 1 R5 opt JP2 CIS C6 opt CI C8 opt R7 opt (default) IMON JP3 R6 opt N 2 1 2 1 3 3 LDC MDA LDA LDC LDAMDC M D2 P C3 100nF opt C4 MD GND LDK LDA N-TYPE LASER DIODE DRIVER GND2 NERR CID TTL EN JP10 LVDS 9 VSY VSY 10 SYN 2 AVG AVG EP 3 JP7 ON 20 REGE C7 100nF JP6 Cext 22 NSLP R2 2.74k JP4 ILIM OFF REGE JP5 VSY NSLP 2 1 R3 1k D3 RD SYN C2 opt 3 C1 100nF VDD iC-NZN ar y n i im prel Rev B1, Page 15/17 EVALUATION BOARD iC-NZN comes with an evaluation board for test purpose. Figures 10 and 11 show both the schematic and the component side of the evaluation board. Figure 10: Schematic of the evaluation board iC-NZN N-TYPE LASER DIODE DRIVER ar y n i im prel Rev B1, Page 16/17 Figure 11: Evaluation board (component side) iC-Haus expressly reserves the right to change its products and/or specifications. An info letter gives details as to any amendments and additions made to the relevant current specifications on our internet website www.ichaus.de/infoletter; this letter is generated automatically and shall be sent to registered users by email. Copying – even as an excerpt – is only permitted with iC-Haus’ approval in writing and precise reference to source. iC-Haus does not warrant the accuracy, completeness or timeliness of the specification and does not assume liability for any errors or omissions in these materials. The data specified is intended solely for the purpose of product description. No representations or warranties, either express or implied, of merchantability, fitness for a particular purpose or of any other nature are made hereunder with respect to information/specification or the products to which information refers and no guarantee with respect to compliance to the intended use is given. In particular, this also applies to the stated possible applications or areas of applications of the product. iC-Haus conveys no patent, copyright, mask work right or other trade mark right to this product. iC-Haus assumes no liability for any patent and/or other trade mark rights of a third party resulting from processing or handling of the product and/or any other use of the product. As a general rule our developments, IPs, principle circuitry and range of Integrated Circuits are suitable and specifically designed for appropriate use in technical applications, such as in devices, systems and any kind of technical equipment, in so far as they do not infringe existing patent rights. In principle the range of use is limitless in a technical sense and refers to the products listed in the inventory of goods compiled for the 2008 and following export trade statistics issued annually by the Bureau of Statistics in Wiesbaden, for example, or to any product in the product catalogue published for the 2007 and following exhibitions in Hanover (Hannover-Messe). We understand suitable application of our published designs to be state-of-the-art technology which can no longer be classed as inventive under the stipulations of patent law. Our explicit application notes are to be treated only as mere examples of the many possible and extremely advantageous uses our products can be put to. iC-NZN N-TYPE LASER DIODE DRIVER ar y n i im prel Rev B1, Page 17/17 ORDERING INFORMATION Type Package Order Designation iC-NZN QFN24 4 mm x 4 mm Evaluation Board iC-NZN QFN24 iC-NZN EVAl NZN1D For technical support, information about prices and terms of delivery please contact: iC-Haus GmbH Am Kuemmerling 18 D-55294 Bodenheim GERMANY Tel.: +49 (61 35) 92 92-0 Fax: +49 (61 35) 92 92-192 Web: http://www.ichaus.com E-Mail: [email protected] Appointed local distributors: http://www.ichaus.com/sales_partners